\\[-1.8ex] Soil Heterogeneity & $-$0.032$^{*}$ & $-$0.023 & $-$0.027 & $-$0.030 & $-$0.034$^{*}$ & $-$0.035$^{*}$ & $-$0.035$^{*}$ \\ 
  & (0.019) & (0.019) & (0.019) & (0.019) & (0.019) & (0.019) & (0.020) \\ 
\\[-1.8ex]
Observations & 23,532 & 23,532 & 23,532 & 23,532 & 23,532 & 23,532 & 23,532 \\ 
R$^{2}$ & 0.677 & 0.676 & 0.676 & 0.676 & 0.677 & 0.677 & 0.677 \\ 
